Try NBD-PC.  It is a fluorescently tagged phospholipid which we use for
demonstrating FRAP (Fluorescence Recovery After Photobleaching) experiments on
our Ultima.  It comes as a liquid in glass vials, which can be dissolved
directly in oil or diluted down for use in membrane kinetics experiments.  The
fluorescence spectra are exactly as you describe, a nice sharp peak at around
520.  It does bleach more readily than you would like for morphological work,
but for staining a bulk liquid or for FRAP it works very well.

David Carter
Insight Biomedical Imaging Inc.
919 Filley St
Lansing MI 48906

tel. 517 327 0950
fax 517 327 0959

In a message dated 4/13/98 11:12:15, [log in to unmask] wrote:

<<Dear list subscribers,
I am looking for a fluorescent stain for immersion oil, that shows similar
fluorescence properties as fluorescein (excitable with 488, emission around
520 nm). We find that neiter fluorescein nor FITC is well fluorescent when
solved in oil.
Can anybody suggest an alternative?

Thanks in advance,
Ulrich Kubitscheck
>>